Fukushiro Nukaga, the Japanese defence minister, said on Sunday after a three-hour meeting with Donald H Rumsfeld, the US defence secretary, that Japan wanted to have an appropriate sharing of costs in transferring 8,000 marines from Okinawa to the Pacific island of Guam.
Japan has offered to pay $2.8bn and the rest of its $6.1bn share will be in loans. Japan would shoulder 59% of the realignment cost.
Nukaga said both sides agreed that the Japan-US alliance is important, not only for Japan but also for the region.
The US had proposed in an earlier round of negotiations that Japan pay $7.5bn, or 75%, of the cost to relocate marines. Japan had said it would pay about one-third of that amount.
The US and Japan are discussing the biggest restructuring and streamlining of the US military based in Japan in decades.
An outline of the overall realignment plan was announced in October and was to be finalised by the end of March. However, it got bogged down over details.
Under a mutual security pact, the US has about 50,000 troops stationed in Japan. The presence includes more than 10,000 marines, several air bases and the home port for the Navy's 7th Fleet.